A new method to comprehensively evaluate the quality of Tianma Toutong tablets by multiple fingerprints combined with quantitative analysis and prescription analysis

Tianma Toutong Tablets (TMTTTs) are composed of six traditional Chinese medicines (TCMs), and there is currently no comprehensive method to evaluate the quality of TMTTT. To ensure its quality, it is necessary to propose methods for evaluation and control. To address the issue, we established an HPLC and electrochemical fingerprint of TMTTT and quantify eight components-Gastrodin, p-hydroxybenzyl alcohol, chlorogenic acid, parishin A, ferulic acid, hesperidin, imperatorin, and isoimperatorin. We used the Sub-quantified profiling method (SQPM) to calculate the actual contribution value of each individual herb and evaluated and predicted the quality of the compound medication. In addition, electrochemical fingerprinting (ECFP) was established using a Belousov-Zhabotinsky (B-Z) oscillation system in which six characteristic electrochemical parameters were recorded to compare the differences between batches. Finally, a compound synthesizing fingerprint (CSF) of TMTTT was developed by fitting the compounds of the six herbs, the contribution of individual herbs to the prescription was evaluated. Principal component analysis (PCA) was used to downscale the data of different fingerprint profiles to assist the analysis process. The rational combination of multidimensional fingerprinting and PCA provided a comprehensive and reliable method for the evaluation of TMTTT and other TCM compound preparations, SQPM could effectively link single herbs to compound preparations, avoiding the use of non-compliant TCMs at source and improving the quality of compound preparations.

Quality assessment of Red Yeast Rice by fingerprint and fingerprint-effect relationship combined with antioxidant activity

Red Yeast Rice (RYR) is an important functional food ingredient that plays a critical role in promoting dietary guidance and maintaining health. To ensure its quality, four key compounds were quantified, and both HPLC fingerprint and electrochemical fingerprint (ECFP) were applied to assess quality. Additionally, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+•) scavenging test and ECFP were applied to assay the total antioxidant activity, with ascorbic acid as the positive control. The results showed that the holistic quality of samples was divided into 4 grades based on HPLC fingerprint analysis by the comprehensive linear quantitative fingerprint method. Additionally, the area of the total peak (Atp) in ECFP was found to be linearly correlated with the antioxidant activity (R > 0.99). A further fingerprint-efficacy relationship analysis determined the significant contributions to the antioxidant activity of peaks 20-Daidzein, 21-Glycitein, and 24-Genistein. Overall, this study suggested a comprehensive and reliable approach to the quality assessment of RYR.

Enhancing quality evaluation in traditional Chinese medicine: Utilizing dual wavelength fusion fingerprint, electrochemical fingerprint, and DSC fingerprint

Developing a reliable and effective quality evaluation system for traditional Chinese medicine (TCM) is both challenging and crucial for its advancement. This study employs fingerprinting techniques to establish precise and comprehensive quality control for TCM, taking Xuezhikang capsules as an example and aiming to facilitate the internationalization of TCM. The "double wavelength absorption coefficient ratio fingerprint" and "Reliability theory" are developed to determine the fingerprint peak purity and fingerprint reliability respectively. Subsequently, the dual-wavelength fusion fingerprint was obtained to avoid the limitations of a single wavelength. In addition, an electrochemical fingerprint (ECFP) was obtained to assess the similarity of electroactive components in the sample, and the Differential Scanning Calorimetry quantized fingerprint (DSC QFP) was introduced for thermal analysis. Fingerprint-efficacy correlations between PL-EC* and dual-wavelength fusion fingerprint (DWFFP) provided valuable insights that there are 76.6 % of the fingerprint compounds exhibited electroactivity. Finally, samples were classified into grades 1∼3 by combining DWFFP, ECFP and DSC QFP through the mean method, meeting the evaluation standard (SL-M > 0.9, PL-M between 80 % and 120 %). This study provides valuable information for ensuring the quality of TCM products, which represents a significant step forward in enhancing the reliability and authenticity of TCM products.

Quality evaluation of Keteling capsules based on fingerprinting, multicomponent quantification, and quantitative prediction

The Keteling capsule (KC) is a traditional Chinese medicine (TCM) made from the dried extract of Ficus microphylla and an appropriate amount of chlorpheniramine maleate. It is widely used to treat cough and relieve asthma. Despite its extensive usage, a rapid and comprehensive quality evaluation strategy for KC remains a challenge. This study introduces an electrochemical fingerprint analysis technique, in addition to the commonly employed HPLC fingerprints, for efficient and convenient quality evaluation. Moreover, a cost-effective, rapid, and accurate multi-component quantification technique known as the "Multi-markers assay by the monolinear method (MAML)" and the "FT-IR quantitative model" were explored. The HPLC fingerprints were evaluated using a systematically quantified fingerprint method, while the electrochemical fingerprints, based on the Belousov-Zhabotinsky oscillation reaction principle, were effectively analyzed and characterized using oxidation induction times and oscillation lifetimes. Multi-component quantitative analysis was carried out through the MAML and FT-IR quantitative models. The HPLC fingerprint successfully classified the 22 samples into eight grades with excellent discrimination. Active ingredient content analysis was achieved using reliable parameters obtained from electrochemical fingerprinting. The no significant difference in the quantitative results proves the accuracy of the MAML method. Additionally, successful FT-IR quantitative prediction models were developed for chlorogenic acid, isovitexin, and chlorpheniramine maleate. This study offers a dependable and effective approach for enhancing the quality control of KC, and it can provide new insights for improving the quality analysis methods in the field of TCM.

Evaluating the quality consistency of antiviral oral liquid by high-performance liquid chromatography five-wavelength matched average fusion fingerprint combined with electrochemical fingerprint and ultraviolet spectral quantum fingerprint

The antiviral oral liquid (AOL) was an antiviral drug currently in clinical trials against coronavirus disease 2019. This study aimed to improve its quality consistency evaluation method using fingerprint techniques from several aspects. First, the five-wavelength matched average fusion fingerprint (FMAFFP) for HPLC, electrochemical fingerprint (ECFP), and ultraviolet spectral quantum fingerprint (UVFP) was established for 22 samples, respectively. Their quality was then assessed using the average linear quantitative fingerprint method, and 22 samples were classified into eight quality grades. OPLS and PCA were then used further to explore the characteristic parameters of these three fingerprints. Five compounds were quantified simultaneously for the first time, and then the relationship between the average linear quantitative similarity (P_L) and the sum of the five quantitative components (P_5c) was investigated. A linear correlation (r ≥ 0.9735) between P_L and P_5c suggested that P_L may be used to predict chemical content. Finally, to investigate the antioxidant potential of the AOL, correlation analyses were performed for FMAFFP peaks-P_EC and UVFP peaks-P_EC, respectively, where the P_EC value was defined as the quantitative similarity of ECFP. The Pearson correlation coefficient and gray correlation analysis were consistent, allowing us to initially explore the antioxidant capacity of the unidentified components of the samples. This study researched AOL using multidimensional fingerprints to provide a comprehensive and reliable method for quality consistency control of herbal compound preparations.

Quality control of Hugan capsule based on four-wavelength fusion profiling and electrochemical fingerprint combined with antioxidant activity and chemometric analysis

Improving the quality standard system of herbal preparations (HPs) is an arduous task for the development of traditional Chinese medicine (TCM). At present, an urgent task is to establish a comprehensive, scientific and effective evaluation method for improving the safety, effectiveness and quality consistency of HPs. In this study, Hu Gan capsules (HGCs) were used as an example. Firstly, the three quality markers (Q-markers) in 21 batches of HGCs from 4 manufacturers were determined by HPLC and great difference in content of each sample was found. Furthermore, four-wavelength fusion profiling (FWFP) was established and evaluated by systematically quantified fingerprint method (SQFM). Principal component analysis (PCA) was employed to make a preliminary analysis of the FWFP and distinguish the fluctuation of differences in chemical composition and content. Then, 9 characteristic parameters were recorded through the B-Z oscillating system, and the electrochemical fingerprint (ECFP) was constructed for jointing evaluation with the FWFP, using the equal weight of SQFM results to comprehensively evaluate the sample quality. The 21 batches of samples were divided into four groups and six grades, which indicated that there were significant differences in the content of indicator components and electrochemical active substances in samples. Finally, taking vitamin C as a positive control, 2, 2'-azino-bis (3 - ethyl -benzthiazoline - 6 - sulfonic acid) (ABTS) scavenging assay was applied to study the antioxidant activity of samples. Partial Least Squares (PLS) and bivariate correlation analysis (BCA) were used to analyze the fingerprint-efficacy relationships of FWFP-ABTS and FWFP-ECFP. Consequently, it was found that there were similar antioxidant capacities in electrochemistry and ABTS tests, and 31 of the 40 HPLC fingerprint peaks of HGCs were discovered to have antioxidant activity. The two methods supported each other, to effectively and corporately reflect the antioxidant components in HGCs. In this research, the FWFP and ECFP established could realize the quality detection of HGCs, and provide a novel direction for the improvement of the quality standard of HPs and the research of the quality standard method of TCM.

Electrochemical and phylogenetic comparisons of oxygen-reducing electroautotrophic communities

The mechanisms of extracellular electron transfer and the microbial taxa associated with the observed electroactivity are fundamental to oxygen-reducing microbial cathodes. Here we confirmed the apparent 'electroautotrophic' behavior of electroactive biofilms (EABs) grown on carbon electrodes at + 0.20V vs. Ag/AgCl under air. The EABs catalyzed O₂ electroreduction into water ─ as demonstrated by a rotating ring disc experiment ─ and performed quasi-reversible heterogeneous electron transfer (HET). By using electrodes of low surface capacitance, we report for the first time nonturnover redox peaks that are very likely intrinsic to the redox protein(s) performing the HET. Because the formal potential of redox proteins is pH-dependent, we investigated the evolution of characteristic potentials of the EABs with the solution pH: (i) open circuit potential, (ii) half-wave potential, and (iii) averaged peak potential of nonturnover cyclic voltammograms, which is presumably the formal potential of the primary electron acceptor(s) for the community. In addition to describing the redox thermodynamics behind HET, we suggest that the corresponding data provides an electrochemical fingerprint that could help in comparing the electroactivity of diverse microbial communities. The taxon with the highest relative abundance in our EABs was an unclassified member of the Gammaproteobacteria that was phylogenetically closely related to most other abundant unclassified Gammaproteobacteria commonly reported in EABs reducing O₂ at high potentials, further suggesting that those taxa are responsible for the bioelectroactivity. Phylogenetic and electrochemical similarities between reported EABs jointly support the hypothesis that similar biomolecular mechanisms may be responsible for this highly probable electroautotrophic metabolism.

An electrochemical method for plant species determination and classification based on fingerprinting petal tissue

The identification of plant species not only is a hobby but also has important application value in plant resources science. Traditional plant identification often relies on the experience of botanists. The infrageneric identification of plants is easily mistaken due to similarities in organ features. In this work, we propose an electrochemical method to obtain fingerprints of plant petal tissue. Fourteen species of Lycoris were used as a model for validating this methodology. Pattern and color recognition were established for visualization of electrochemical fingerprints recorded after various solvent extractions. In addition, the infrageneric relationships of these Lycoris species were deduced from the electrochemical fingerprints since the type and content of electroactive compounds in plants are controlled by genes. The results indicate that the electrochemical fingerprints of Lycoris petals are correlated with the infrageneric relationships of native Lycoris species.